Ruby on Rails Improper Neutralization of Input During Web Page Generation (Cross-site Scripting) Vulnerability - CVE-2013-1855
The sanitize_css method in lib/action_controller/vendor/html-scanner/html/sanitizer.rb in the Action Pack component in Ruby on Rails before 2.3.18 3.0.x and 3.1.x before 3.1.12 and 3.2.x before 3.2.13 does not properly handle n (newline) characters which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via crafted Cascading Style Sheets (CSS) token sequences.